Reasoning Logically, Being Rational and Thinking Scientifically

I stumbled across this short discussion between Neil de Grasse Tyson and Richard Dawkins - names which would usually would send me heading for a Scotty Kilmer car maintenance clip - and at one point Tyson says “[We] must have a great challenge before us to think rationally, logically, scientifically” as if the three were the same, or at least,very similar.



Except these are three very, very different things.

Reasoning logically has a narrow and a broad sense: the narrow meaning is using valid rules of inference to deduce one statement from others; the broader one is conducting an argument in which no two of your assertions contradict each other. The broad interpretation lets you use the full range of informal argument and rhetorical devices. The narrow one is for mathematicians and logicians constructing formal proofs. Most people reason logically in the second sense.

Being rational is not a way of arguing or thinking, but an attitude towards one’e beliefs. The dominant theory of rationality was confirmationism: my belief in something is rational if I have evidence for its truth. Of course fanatics can have evidence for their beliefs, and it really shifts the argument to what constitutes evidence. Try having a discussion with a religious fundamentalist who maintains that there is something called “spiritual evidence” for their bigoted beliefs. Or stand outside on a sunny day and tell me the sun is not moving across the sky: who you going to believe: Copernicus or your lying eyes? So in the 1930’s Karl Popper proposed a falsificationist account of rationality: my belief in something is rational if I am prepared to state the circumstances under which I would abandon that belief. Instant banishment of fanatics, ideologists, psycho-analysts, vulgar evolutionists and a classroom of others to the Naughty Step. The nice thing about this is that anyone putting forward a silly condition - such as an angel coming to the House of Commons and announcing that we should abandon our belief in abortion - tends to sound silly of their own accord.

Thinking scientifically is a process that aimed at finding explanations of empirical phenomena by using previously established explanations, deductive logical reasoning and mathematics, testing those explanations by experiment, and abandoning at least one of the inputs to the test if the experiment fails. (Notice that one of those inputs is: "the experimental result was calculated or measured correctly”. Experimenters can make mistakes as well.) What would non-scientific thinking look like? Usually it doesn’t refer to previous results. It has Gods that just do stuff with no explanation as to why they didn’t do something else. Or else it seems to be able to explain everything, no matter what happens. But above all, pseudo-science and myth are definitive and final. Science is never final and never definitive (except possibly in a grant proposal), it’s a process that aims to improve our understanding of the world, while recognising that at any time, something may come along that is inconsistent with what we think we know, yet gives better results.

Finally, how a scientist finds the explanations, or how a mathematician finds their proof, and where and how they get their ideas, is entirely up to them. They don’t have to follow rules or templates, though there are rules and templates to follow, they just have to be right.

A little later Tyson says that people who think irrationally “get along just fine in life, they live long lives…”. I get the point he’s making, but it applies as long as they don’t reason irrationally about buses, cholera, bullets, stepping out of fifth-floor windows, hungry tigers, drinking poison and other such stuff. Being dumb about the composition of the outer planets is fine, being dumb about running across busy roads is not.

But after that Tyson suggests that Van Gogh is “illogical” for painting Starry Night, and Dawkins suggests that the instincts humans allegedly developed on the savannah for surviving back in the day are also “illogical”. It’s at this point I leave them to it, because jeez! do people even still think like that?

Just because Van Gogh didn’t paint like a Victorian academician doesn’t make his art crazy, although you’re welcome to use words as you want, and if you think Starry Night is crazy, then I’d suggest to you that some good art is crazy. And as for tested survival instincts being “illogical”, well, same thing, if that’s how you want to use the words, then some “illogical” beliefs or behaviours are useful and prudent. As in all things, you do what works.